Open Source Image De-Noising

GREYCstoration is an open-source tool able to de-noise, inpaint, or resize 2D color images. This is a command-line program developed by the IMAGE team of the GREYC Lab in France and is available for Unix, Mac, and Windows systems under the CeCILL license. The algorithm is based on anisotropic diffusion partial differential equations. These equations are able to smooth an image while preserving its main structures. The demo page presents interesting examples of color image de-noising and reconstruction. This is a serious free alternative to commercial products like Noise Ninja or Neat Image that perform the same kinds of operations. The tool is still a little bit hard to use (command-line based), but I hope the simple C++ API will ease the integration of the algorithm in more user-friendly interfaces. Previous versions of GREYCstoration are already available in Digikam and Krita.

Comments

Artificial noises

[biocute]

It seems to perform a lot better when dealing with artificially-added noises than real-life images, as if it already knows how to tackle them.

This pyramid photo has basically been 'ruined' after the denoising, I wonder if we added some synthetic noises in the background while leaving the stone face as is, would this app be able to denoise correctly?

Does it work on 12 or 16 bits/channel images?

[kcbrown]

This tool looks very cool, but today's semi-pro and pro (and even some consumer grade) cameras will store their images in a raw format which preserves 12 bits per color channel at a minimum.

GIMP can't deal with these. Tools such as ufraw can convert them to 8 bits/channel images such as JPEG but don't allow you to actually manipulate the image in its native color resolution.

Linux seriously needs a good image manipulation tool such as the GIMP with 16-bit or even 32-bit per color channel support built-in. This is particularly important for operations like sharpening.

Cinepaint will do it but it's way behind in features compared with GIMP these days.

What's the hold up with GIMP anyway? You'd think its developers would take this kind of issue seriously and would fix the engine to natively do, say, 32 bits per color channel internally.

Same effect

[rez_rat]

by taking off my glasses!!

I don't see what the point is

[iPaul]

I keep pressing my ear to my computer, but the pictures don't make any noise. They're actually pretty quiet.

Image reconstruction with resynthesizer

[tjwhaynes]

Another tool which can be used to remove objects from pictures is Resynthesizer. I've used this to remove overhead wires from photos, create more sky for a panorama and clean up dust spots of scans successfully.

It can also take one image and repaint it in the style of another image, so you can take a black and white photo and a pencil sketch as inputs and end up with your photo rendered using parts of the pencil image which are similar in form.

Another trick it can pull is creating tileable textures from any image. Sometimes the results are a little surprising if you start off with a picture of people at a party but they are totally seamless.

It comes as a GIMP plugin and is easy to use if you are used to the GIMP.